Power/PowerPC RIOS/RIOS2 obsolescence

[Segher Boessenkool]

[I proposed removing RIOS support, since it heavily gets in the way
for my project exposing the XER[CA] flag].

> My argument is simply this, sorry if it wasn't clear in the last
> email, bottom line up front:
> - It can just as easily be removed in the future if it is broken for
> more than one release rather than evicting support.

I can guarantee you that the changes I am trying to make _will_ break
RIOS support.  RIOS handles the carry flag quite differently from
PowerPC and Power Architecture, and I have no way to test RIOS either.
Since there is no significant community using these chips anymore,
removing RIOS support seemed like the best course of action.

> - It shouldn't add unwieldy maintenance overhead.

It already HAS been unwieldy maintenance overhead for years.

>   The old stuff can
> be walled off, conditionally built, and otherwise removed from the
> main focus.

You obviously haven't looked at the code in detail, if you think this.

> - The code is already written and just needs a maintainer.
> - I have the hardware and desire to maintain it.

Feel free to split off a new backend then.  The current intertwined
mess cannot be maintained properly.


Segher